CLINICAL PATHOPHYSIOLOGICAL STUDIES ON THE MEASUREMENT OF RIGHT VENTRICULAR EJECTION TIME AND MECHANICAL EFFECT. I. EXAMINATION OF METHOD OF MEASURING THE RIGHT VENTRICULAR EJECTION TIME

Abstract

EXAMINATION OF METHOD OF MEASURING THE RIGHT VENTRICULAR EJECTION TIME Cardiopulmonary hemodynamics has been clarified by the development of venous catheterization and examinations of coronary circulation and myocardial metabolism have become possible on human bodies. The ventricular mechanical work, chiefly of the left heart, was determined by DEXTER, KATZ, RODBARD and SARNOFF. With the rapid development of studies on pulmonary circulation, importance has come to be attached on observation of the mechanical effect of the right ventricle. The ventricular mechanical work seems to be done during the period in which the arterial valves are open. To investigate the right ventricular mechanical effect, the author considered it essential to confirm the method of measuring the ventricular ejection time. Method and Materials The tip of a double lumen catheter is placed in the trunk of the pulmonary artery with its side hole in the right ventricle and through V. basilica. The pressure curves of both the right ventricle and pulmonary artery are recorded on an Oscillographic paper, simultaneously with the electrocardiograph and phonocardiograph. Among 1 6 patients investigated in this study, eight with cardiovascular disease, six with chronic pulmonary disease and two others were free from evidence of congestive heart failure. Patients with congenital heart failure or atrial fibrillation were not used in this study. The heart rate, systemic blood pressure and hemoglobin cntents of these cases were all within the normal range. Result and Discussion 1 ) Measurement with a Double Lumen Catheter : In the simultaneous recording of the right ventricular and pulmonary arterial pressure curves, duration between the first intersecting point and the second intersecting point, of these pressure curves was 0.23 seconds, which is 30.4 %±4.4 % of the R-R time. This period does not correspond exactly with the systolic phase, but includes the protodiastole. It is highly probable that the right ventricle performs some ejection work in this protodiastolic phase, because the right ventricular pressure is higher than the pulmonary arterial until the second intersecting point of the two curves during which the pulmonary valve is kept open. It may therefore be induced that the time, including the abovementioned period. which is required until the second intersecting point, corresponds to the right ventricular ejection time.